hifi engine

Deck Alpine Alpage AL-50

Good morning to all of you
Some of you could help me?
I need the service manual of the deck alpage alpine AL-50. My cassette deck mysteriously stopped recording, the worst is that the failure is intermittent, unable to so far to find the cause. All the revisions made so far give perfect. I think without the manual I can not resolverl the problem. Because I lack the necessary data.
Thank you very much for the help they can offer.
I take this opportunity to greet all of you